For convenience at medical sites, pre-filled syringes and pre-filled vials filled with pharmaceuticals in advance and the like are manufactured. A work for filling pharmaceuticals in these syringes and vials is performed in a filling work room under an aseptic environment (hereinafter referred to as an aseptic work room). The individual syringes and vials and the like used in this work are small, and the large quantity is needed to be treated. Thus, these syringes and vials and the like are sterilized by γ-ray irradiation, electron beam irradiation, EOG (ethylene oxide gas) and the like in the respective manufacture stages and carried into the aseptic work room in a state collected in a predetermined number and accommodated in a package.
This type of package includes a medical instrument package proposed in the following Patent Literature 1 or described as a prior art (see FIG. 1) and the like. These packages are generally called peel-open packages and are provided with a plastic tab molded in conformity with the shape of an article such as a syringe or a vial to be accommodated therein and an air-permeable upper-surface seal. For this upper-surface seal, an unwoven cloth made of high-density polyethylene extremely thin fibers, Tyvek (registered trademark) is generally used, and air can permeate the inside of the plastic tab through fine holes of this Tyvek (registered trademark), but intrusion of microorganisms is prevented.
The package configured as above is further packed on an outer part thereof with packing paper and distributed/transported. However, during distribution or transportation, or when it is taken out of the packing bag in order to be carried into the aseptic work room, the plastic tab and the outer packaged surface of the upper surface seal are contaminated. Therefore, the package cannot be carried into the aseptic work room unless the contaminated outer packaged surface is sterilized. Thus, the plastic tab and the outer packaged surface of the upper surface seal are sterilized by a sterilizing device provided continuously to the aseptic work room and then, carried into the aseptic work room, the upper surface seal is peeled open from the plastic tab in the aseptic work room, and a filling work is performed into the sterilized syringes and vials therein.
For these sterilizing devices, various methods such as EOG (ethylene oxide gas), hydrogen peroxide low-temperature gas, ozone gas, plasma, γ-ray irradiation, UV-ray irradiation, electron beam irradiation and the like are employed in accordance with the purpose. One of the most widely-used methods among them is the method by using hydrogen peroxide low-temperature gas.
In the method by using hydrogen peroxide low-temperature gas, a sterilization effect at a required level can be obtained, but certain treatment time is needed to sterilize the entire package, and if the hydrogen peroxide low-temperature gas intrudes into the plastic tab through the upper surface seal made of Tyvek (registered trademark), time for removing the hydrogen peroxide coagulated inside is required, which is a problem.
Thus, in the sterilizing device requiring treatment of a large quantity of articles per unit time as manufacture of a pre-filled syringe, a method with high sterilization effect in a short-term treatment is in demand. Thus, in the following Non-Patent Literature 1, a sterilizing device incorporating a low-energy electron accelerator is introduced as a safe device which can obtain a higher sterilization effect and higher productivity with no remaining substance as compared with general devices using hydrogen peroxide low-temperature gas.
This sterilizing device is actually operated for treatment of the package accommodating the prefilled syringes, and the package with the syringe subjected to sterilization treatment in advance therein is sterilized on its outer packaged surface with an electron beam and conveyed to the aseptic work room by a conveyer. This device performs irradiation by three low-energy electron accelerators arranged by an angle of 120 degrees from each other to the whole surface of the package from three directions (see FIG. 9).
In this device, the plastic tab and the upper surface seal can be efficiently sterilized by controlling a dose of the irradiated electron beam. According to the following Non-Patent Literature 1, 3600 syringes per hour can be treated by this device, and high productivity is realized.